In the previously known processes the measurement of the muzzle velocity is undertaken by an additional device which is fitted to the launching barrel of the barrel weapon. This device consists of a magnetic-field sensor, with a permanent magnet arranged in the projectile. By virtue of the movement of the projectile and hence of the permanent magnet in the launching barrel, a current is induced in the magnetic-field sensor. The velocity can be calculated from two measurements performed consecutively.
The following disadvantages arise from this:
1. The information pertaining to the muzzle velocity is initially available only in the external measuring device on the launching barrel and then has to be transferred to the detonator or to the detonator electronics in the projectile.
2. The transfer of the muzzle velocity is preferably effected in wireless manner, representing an additional technical effort.
3. In the case of shoulder-supported barrel weapons (hereinafter also called shoulder-launched weapons) the length, and in particular the weight, of the weapon is extended by the external measuring device. For ergonomic reasons an exceeding of the weight limit is no longer accepted nowadays. An exceeding of the length of the weapon may prevent stowability in personnel carriers.
4. An external measuring device requires an additional power supply, which increases the maintenance effort for weapons of such a type.
5. An external measuring device represents an additional logistical effort.
In EP 0 359 908 A1 a device for setting a time fuse of a projectile is described, the muzzle velocity of the projectile being measured, and the delay-time being corrected by the measured value of the muzzle velocity. For the purpose of ascertaining the muzzle velocity of the projectile the latter exhibits a magnetic-field sensor and the gun-barrel exhibits a first magnetic-field generator. In order to ascertain the projectile velocity very accurately with relatively little instrumental effort, it is proposed that a second magnetic-field generator be arranged on the gun-barrel, hereinafter also called the launching barrel, and that the receiving sensor be connected to a start-stop counter via an amplifier. The counter is started when the projectile flies past the second magnetic-field generator. The counter is stopped when the projectile flies past the first magnetic-field generator. The content of the counter then determines the timing-pulse frequency at which a preset downward counter is counted down.